View at Official ubuntu advisory, NVD, CVE.org · CVE detail
Freshness: upstream tracker timestamp is available; use API updated time as primary recency signal.
CVE-2002-2438 low priority: Ubuntu including 13 source packages (linux, linux-armadaxp, …), 78 status rows across 6 suites (hardy, lucid, natty, oneiric, precise, upstream): DNE 38, not-affected 24, ignored 15, released 1.
firewalls might let some TCP flags combinations pass (e.g. all with RST flag set) and the OS (e.g. Linux) stack would in turn accept a TCP session it might not have accepted otherwise.